Rewrite the expression in the form $k\cdot z^n$. $3\sqrt[4] z\cdot 3z{^{^{\scriptsize\dfrac34}}}=$
Answer: $\begin{aligned} 3\sqrt[4] z\cdot 3z{^{^{\scriptsize\dfrac34}}}&=3z^{^{\scriptsize\dfrac14}}\cdot 3z^{^{\scriptsize\dfrac34}} \\\\ &=3\cdot3\cdot z^{^{\scriptsize\dfrac14+\dfrac34}} \\\\ &=9z^{1} \\\\ &=9z \end{aligned}$